液空硫回收分析方法中英文版.docx

GWS 71 PrincipleThe hydrogen sulphide absorbed in the elementary sulphur is expelled from a melted sample using nitrogen containing ammonia . ammonia accelerate the expulsion of the hydrogen sulphide . The H2S is absorbed in the wash flasks filled with KOH and converted to K2S(1) . the wash flask arranged between with 0.5 n H3PO4 servers to separate elementary sulphur from the gas steam . the K2S-content of KOH is then determined potentiometrically with silver nitrate(2).2KOH+ H2S-K2S+H2O(1)K2S+2AgNO3-Ag2S+2KNO3(2)2 Sampling30-50g liquid sulphur is poured into the weighted sample vessel at the sampling location . the vessel is immediately closed gastight and weighted again in the laboratory . The difference is the quantity of the sample.3 Equipment and Chemicals3.1 Equipment3.1.1 samplevessel: collecting vessel with nozzles and screw cap , see Item 3 on Figure 1 : content:30ml,thread sized 24,suitable for tubes dia . 7.5-9.0mm,Overall length :200 mm.Oil bath with thermostatFlow meter 2-10 I N2/HSealDrying tube,U-shape1 wash flask with sphericak stopper2 wash bottle with frittered stopper(D 1)TitratorSilver/silver sulphide electrodeGlass electrode or other reference electrode3.1.2 ChemicalsAmmonium carbonate “purest”Potassium hydroxide solution , p.a.35% aqueous solutionPhosphoric acid p.a.0.5 nSilver nitrate 0.01 nNitrogen4 ProcedureThe time between taking the sample and making the analysis ought to be kept as short as possible to keep the H2S losses by reaction of H2S with the existing SO2 to sulphur small.The sulphur sample is melted in the oil bath at 130-140and stripped for 2 hours with nitrogen containing about 0.3 vol.% NH3 after flowing through a drying tube filled with ammonium carbonate. The N2 stream is adjust in such a way that 0.1-0.2 l/h nitrogen flow through . The hydrogen sulphide removed with the nitrogen is absorbed in the two KOH wash flasks . The H3PO4 wash flask only serves to remove elementary sulphur from the gas stream . Elementary sulphur is to be prevented from entering in the KOH where it forms polysulphide and is in part hydrolysed so that high H2S values are obtained . Both KOH quantities are combined and titrated with n/100 AgNO3 potentiometrically.Prior to starting the analysis , all wash flask are to be thoroughly purged with nitrogen to remove oxygen.The arrangement of the apparatus is to be seen from the figure 1. 1) Seal 2) Drying tube with ammonium carbonate3) Sampling vessel with sulphur4) Oil bath with thermostat5) Spherical stopper wash flask with 0.5n PO46,7)Frittered stopper wash flask with 35% KOH5 Calculation1 ml n/100 AgNO3-0.1702 mg H2SExample42.5 g sulphur sample6.5 ml n/100 AgNO3 consumptionConcentration:=26.03 H2S/kg sGWS 7硫磺中的H2S硫磺中H2S的测量方法1 原理将含H2S的原始硫融化，再通入含有氨气的氮气使H2S排出，氨气能加速硫化氢的脱除，在装KOH溶液的洗瓶中，硫化氢被吸收，并转换为K2S(1).用装有0.5N 的H3PO4，用于脱除气流中的单质硫。之后，KON中的K2S组分用硝酸银精确确定。2 KOH + H2S = K2S + 2 H2OK2S + 2 AgNO3 = Ag2S + 2 KNO32 样品在取样地点，将30-50g液态硫磺样品倒入已知质量的样品罐中，立刻将样品罐密封，并在实验室重新称重。两次质量之差就是样品重量。3 设备和试剂3.1 设备3.1.1 样本容器：收集瓶管嘴带有螺帽，见图一第三项；规格：30ml，螺纹规格 24，适合的管径为：7.9-9mm，全长200mm, 油浴恒温流量计 2-10LN2/h密封干燥管，U型洗瓶1带有球型瓶塞洗瓶2带有frittered 瓶塞滴定仪硫化银电极玻璃电极或其他参考电极。3.1.2 化学试剂碳酸铵（最纯的）35%的氢氧化钾水溶液磷酸 0.5N硝酸银 0.01N氮气4 步骤在取样和进行分析之间，尽可能的保持较短的时间，防止硫化氢和存在的二氧化硫反应生成单质硫。硫磺样品在130-140的油浴中融化，并用氮气经过装满碳酸铵的干燥管气提2小时，这时候氮气中约含有0.3%的氨。通过的氮气流量调整至0.1-0.2L/h。硫化氢被氮气脱除，同时在两个氢氧化钾洗瓶中吸收。磷酸洗瓶用于脱除气流中的单质硫，防止单质硫进入KOH溶液中，生成多硫化合物和发生部分水解反应生成更多H2S。氢氧化钾溶液用0.01NAgNO3滴定。分析前，所有的洗瓶都要用氮气置换，将氧气脱除。装置排布参照图11）密封2）装有碳酸铵的干燥管3）硫磺样品罐4）油浴恒温槽5）装有0.5n磷酸的球型瓶塞洗瓶6、7）装有35%氢氧化钾的洗瓶5 计算1 ml n/100 AgNO30.1702 mg H2S例子：42.5g 硫磺样品消耗6.5ml n/100 AgNO3结论GWS 11 1. PrincipleSulphur dioxide is oxidized with hydrogen peroxide to sulphuric acid which is determined by titration with caustic soda solution . Hydrogen sulphide is not converted in sour H2O2 solution.SO2+H2O2-H2SO4H2SO4+2NaOH-Na2SO4+2H2OIn acetate solution the hydrogen sulphide contained in the gas together with zinc acetate forms zinc sulphide which is determined iodometrically.H2S+Zn(CH3COOH)2-ZnS+2CH3COOHZnS+2HCl-H2S+ZnCl2H2S+2HI+S+I2(surplus)+2NaS2O3-2NaI+NaS4O62. Equipment and ChemicalsGas collecting tubes 0.5-11(gauge)Gas wash flask to Drechsel, without frit, 150ml T-pieces Pinch valvesPVC tubeErlenmeyer flask, 500mlHydrogen peroxide solution,3%Zinc acetate solution ,4% Zn-acetate,10% acetic acid0.1 n caustic soda solution Methyl red solution Hydrochloric acid , concentrated0.1 n iodine solution0.1 n thiosulphate solutionStarch solution 3. Sampling and Analysis1 Gas line2 Sampling cock3 T-piece4+5 Pinch cocks6+7 Water flask with H2O28 Wash flask with Zn-acetate9 Gas collecting tube10 Water drainThe apparatus is arranged in accordance with the above drawing. The gas wash bottoms are filled with 80-100 ml solution. If the gas sample contains no elementary sulphur the first wash flask with H2O2 be dispensed with. Should the solution foam during sampling , this can be prevented by adding 4-5 drops amyl alcohol per wash flask. The gas collecting tubes are to be filled with water before taking samples.After connecting the apparatus to the sampling cock,sampling cock 2 is opened somewhat with cock5 closed and cock 6 opened and the connection piece purged for same minutes. Now the top and then the bottom cock of the gas collecting tube are open , the end of connected PVC tube 10 being raised. Same water flows out of the collecting pipe and after opening cock5, gas flows through the wash flask. The velocity ought to be about 30-50 l/h and can be regulated by raising or lowering the end of tube 10 and/or closing cock4 slightly. During sampling , same gas must always blow through purging system 4. Sampling is completed when all water has been expelled from the gas collecting tube ,the end of the tube having been at the elevation of the bottom cock.(Practical tip:tie the end of the tube filled with water at bottom cock before sampling)After closing cock 5 and the collecting tube cocks as well as the sampling cock, the wash flasks are taken off and if possible purged with nitrogen to force the gas above the solutions through the absorbents. If no nitrogen is available, air can be blown through for a short time.The contents of wash flasks 6 and 7arepoured into an Erlenmeyer flask and titrated wih 0.1 NaOH against methl red.In wash flask 8,a surplus of 0.1 n iodine solution and HCl are added. With the frit tube in place, one lets the solution stand in the dark for abt. 10 mintutes, flushes the frit tube and titrates the surplus iodine direct in the wash flask with 0.1 n thiosulphate solution against starch solution as indicator.4. CalculationVSO2ml=1.095*ml consumption NaOHVH2SML=1.107*(ml iodine solution ml thiosulphate solution)VRestml=reduce gas volume of collecting tube(dry)SO2Vol.%;dry= (VSO2*100)/( VSO2+ VH2S+ VRest)H2SVol.%,dry= (VH2S *100)/( VSO2+ VH2S+ VRest)RemarkOn calculating the volume of the gas collecting tube to normal condition, the ambient temperature during sampling can be taken with sufficient accuracy if a collecting tube with thermometer is not available.GWS 11含有CO2情况下检测克劳斯反应气中H2S和SO21 原理二氧化硫被过氧化氢氧化称硫酸，用烧碱溶液滴定测量。硫化氢在酸性的H2O2溶液不能氧化.SO2 + H2O2 = H2SO4H2SO4 + 2NaOH = Na2SO4 + 2H2O在醋酸盐溶液中，气体中的硫化氢和醋酸锌形成硫化锌，可以用滴定碘法测定。H2S + Zn(CH3COO)2 ZnS + 2CH3COOHZnS + 2HCl H2S + ZnCl2H2S + I2(过量) HI + S + I2(剩余)I2(过量) + 2NaS2O3 2NaI + Na2S4O62 设备和化学试剂气体收集管0.5-11（容量规格）气体洗涤烧瓶，with and without frit夹管阀PVC管锥形烧